Transportation of micrometer-sized object and extraction of mechanical work by constant electric field

Abstract

A technique capable of making an object move and transporting it without generation of a current, and extracting mechanical work. As a result of diligent effort, the present inventors have found that by arranging two electrodes for generating an electric field for a dielectric body of a micrometer-size or the like in an insulating fluid such as oil, such that the central axes of the two electrodes are not aligned, and applying an electric field (for example, constant electric field), the dielectric body can be transported three-dimensionally at will, and as a result, mechanical work can be extracted.

The invention claimed is: 
     
       1. An apparatus for transporting a dielectric body comprising:
 an insulating fluid for receiving the dielectric body, the insulating fluid being of different composition to the dielectric body; 
 two electrodes; and 
 a means for applying a constant voltage between the two electrodes to generate a constant electric field, the two electrodes residing in the insulating fluid, the two electrodes having central axes, the central axes running along the center of their respective electrodes and being parallel to the direction of the maximum length of their respective electrodes, the two electrodes being arranged so that their central axes are sufficiently not aligned such that when the constant electric field is applied to a dielectric body, two dimensional cyclic motion of the dielectric body is generated. 
 
     
     
       2. The apparatus according to  claim 1 , wherein the diameter of said dielectric body is of a micrometer-size, and the micrometer-size ranges from several nm to 1000 μm. 
     
     
       3. The apparatus according to  claim 2 , wherein said micrometer-size ranges from 1 μm to 100 μm. 
     
     
       4. The apparatus according to  claim 1 , wherein said dielectric body is a substance generating dielectric polarization but not generating a current when an electrostatic field is applied, and is a substance having electrostatic chargeability. 
     
     
       5. The apparatus according to  claim 1 , wherein said dielectric body is selected from the group consisting of a water droplet, a polymeric substance and a glass bead. 
     
     
       6. The apparatus according to  claim 5 , wherein said dielectric body is a water droplet, and wherein said water droplet is generated by using a surfactant. 
     
     
       7. The apparatus according to  claim 6 , wherein said surfactant is generated by using at least one substance selected from the group consisting of dioleoyl phosphatidylcholine (DOPC), dioleoyl phosphatidylethanolamine (DOPE), dioleoyl phosphatidylserine (DOPS), eggPC, stearyl trimethyl ammonium chloride (STAC), stearyl trimethyl ammonium bromide (STAB), sodium dodecyl sulfate (SDS), dodecyl trimethyl ammonium chloride and pentaethylene glycol dodecyl ether. 
     
     
       8. The apparatus according to  claim 1 , wherein said insulating fluid is a substance that is non-volatile, non-conductive, and fluent under normal temperature and normal pressure, and has a specific gravity with respect to said micrometer-sized dielectric body of within ±50%. 
     
     
       9. The apparatus according to  claim 1 , wherein said insulating fluid is selected from the group consisting of mineral oil, liquid paraffin, alkane and silicone oil. 
     
     
       10. The apparatus according to  claim 1 , wherein said electric field is subject to the range from 1 V to 1000 V. 
     
     
       11. The apparatus according to  claim 1 , wherein a positive electrode and a negative electrode for generating said electric field are arranged so that their central axes are not parallel with each other. 
     
     
       12. The apparatus according to  claim 11 , wherein said electrode has a pyramid or conical shape having a sharp tip, or a prismatic or cylindrical shape, and has a material having conductivity. 
     
     
       13. The apparatus according to  claim 10 , wherein said electrode is a conductive substance selected from the group consisting of tungsten, tungsten carbide, gold, platinum, silver, copper, iron and aluminum. 
     
     
       14. The apparatus according to  claim 1 , wherein the two electrodes comprise a positive electrode and a negative electrode, and the orientation of the two electrodes is such that the two electrodes are in different directions to each other. 
     
     
       15. The apparatus according to  claim 14 , further comprising a micromanipulator capable of manipulating each of three-dimensional coordinates by 1 μm, the micromanipulator manipulating each coordinate to shift an electrode to a desired position, or further comprising tweezers. 
     
     
       16. The apparatus according to  claim 1 , further comprising a means for transporting said dielectric body by indirectly controlling the dielectric body by spatial control of said electrodes. 
     
     
       17. The apparatus according to  claim 1  for use in mechanical control of a polymer, liquid droplet transportation of a pharmaceutical or chemical, a chemical reaction, pharmaceutical or chemical preparation, non-contact transportation of a biological sample, or a micro-channel. 
     
     
       18. An apparatus for extracting mechanical work, comprising:
 an insulating fluid; 
 a dielectric body arranged in the insulating fluid, the dielectric body being of different composition to the insulating fluid; 
 two electrodes; 
 a means for applying a constant voltage between the two electrodes to generate a constant electric field, the two electrodes residing in the insulating fluid, the two electrodes having central axes, the central axes running along the center of their respective electrodes and being parallel to the direction of the maximum length of their respective electrodes, the two electrodes being arranged so that their central axes are sufficiently not aligned such that when the constant electric field is applied to a dielectric body, two dimensional cyclic motion of the dielectric body is generated; and 
 a means for extracting mechanical work from the dielectric body. 
 
     
     
       19. The apparatus according to  claim 18 , further comprising a micro-turbine. 
     
     
       20. The apparatus according to  claim 18 ,
 further comprising a plurality of dielectric bodies including said dielectric body, and the plurality of dielectric bodies are caused to collectively move to function as a motor.